Import relocation packer from chromium repo

Bug: 18051137
Change-Id: Ia67fa11da8247e3f86f70a8ce99e6695f2c05423
diff --git a/tools/relocation_packer/src/delta_encoder_unittest.cc b/tools/relocation_packer/src/delta_encoder_unittest.cc
new file mode 100644
index 0000000..b9bf39a
--- /dev/null
+++ b/tools/relocation_packer/src/delta_encoder_unittest.cc
@@ -0,0 +1,150 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "delta_encoder.h"
+
+#include <vector>
+#include "elf.h"
+#include "elf_traits.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+void AddRelocation(ELF::Addr addr,
+                   ELF::Sxword addend,
+                   std::vector<ELF::Rela>* relocations) {
+  ELF::Rela relocation;
+  relocation.r_offset = addr;
+  relocation.r_info = ELF_R_INFO(0, ELF::kRelativeRelocationCode);
+  relocation.r_addend = addend;
+  relocations->push_back(relocation);
+}
+
+bool CheckRelocation(ELF::Addr addr,
+                     ELF::Sxword addend,
+                     const ELF::Rela& relocation) {
+  return relocation.r_offset == addr &&
+      ELF_R_SYM(relocation.r_info) == 0 &&
+      ELF_R_TYPE(relocation.r_info) == ELF::kRelativeRelocationCode &&
+      relocation.r_addend == addend;
+}
+
+}  // namespace
+
+namespace relocation_packer {
+
+TEST(Delta, Encode) {
+  std::vector<ELF::Rela> relocations;
+  std::vector<ELF::Sxword> packed;
+
+  RelocationDeltaCodec codec;
+
+  packed.clear();
+  codec.Encode(relocations, &packed);
+
+  EXPECT_EQ(0, packed.size());
+
+  // Initial relocation.
+  AddRelocation(0xf00d0000, 10000, &relocations);
+
+  packed.clear();
+  codec.Encode(relocations, &packed);
+
+  EXPECT_EQ(3, packed.size());
+  // One pair present.
+  EXPECT_EQ(1, packed[0]);
+  // Delta from the neutral element is the initial relocation.
+  EXPECT_EQ(0xf00d0000, packed[1]);
+  EXPECT_EQ(10000, packed[2]);
+
+  // Add a second relocation, 4 byte offset delta, 12 byte addend delta.
+  AddRelocation(0xf00d0004, 10012, &relocations);
+
+  packed.clear();
+  codec.Encode(relocations, &packed);
+
+  EXPECT_EQ(5, packed.size());
+  // Two pairs present.
+  EXPECT_EQ(2, packed[0]);
+  // Delta from the neutral element is the initial relocation.
+  EXPECT_EQ(0xf00d0000, packed[1]);
+  EXPECT_EQ(10000, packed[2]);
+  // 4 byte offset delta, 12 byte addend delta.
+  EXPECT_EQ(4, packed[3]);
+  EXPECT_EQ(12, packed[4]);
+
+  // Add a third relocation, 4 byte offset delta, 12 byte addend delta.
+  AddRelocation(0xf00d0008, 10024, &relocations);
+
+  // Add three more relocations, 8 byte offset deltas, -24 byte addend deltas.
+  AddRelocation(0xf00d0010, 10000, &relocations);
+  AddRelocation(0xf00d0018, 9976, &relocations);
+  AddRelocation(0xf00d0020, 9952, &relocations);
+
+  packed.clear();
+  codec.Encode(relocations, &packed);
+
+  EXPECT_EQ(13, packed.size());
+  // Six pairs present.
+  EXPECT_EQ(6, packed[0]);
+  // Initial relocation.
+  EXPECT_EQ(0xf00d0000, packed[1]);
+  EXPECT_EQ(10000, packed[2]);
+  // Two relocations, 4 byte offset deltas, 12 byte addend deltas.
+  EXPECT_EQ(4, packed[3]);
+  EXPECT_EQ(12, packed[4]);
+  EXPECT_EQ(4, packed[5]);
+  EXPECT_EQ(12, packed[6]);
+  // Three relocations, 8 byte offset deltas, -24 byte addend deltas.
+  EXPECT_EQ(8, packed[7]);
+  EXPECT_EQ(-24, packed[8]);
+  EXPECT_EQ(8, packed[9]);
+  EXPECT_EQ(-24, packed[10]);
+  EXPECT_EQ(8, packed[11]);
+  EXPECT_EQ(-24, packed[12]);
+}
+
+TEST(Delta, Decode) {
+  std::vector<ELF::Sxword> packed;
+  std::vector<ELF::Rela> relocations;
+
+  RelocationDeltaCodec codec;
+  codec.Decode(packed, &relocations);
+
+  EXPECT_EQ(0, relocations.size());
+
+  // Six pairs.
+  packed.push_back(6);
+  // Initial relocation.
+  packed.push_back(0xc0de0000);
+  packed.push_back(10000);
+  // Two relocations, 4 byte offset deltas, 12 byte addend deltas.
+  packed.push_back(4);
+  packed.push_back(12);
+  packed.push_back(4);
+  packed.push_back(12);
+  // Three relocations, 8 byte offset deltas, -24 byte addend deltas.
+  packed.push_back(8);
+  packed.push_back(-24);
+  packed.push_back(8);
+  packed.push_back(-24);
+  packed.push_back(8);
+  packed.push_back(-24);
+
+  relocations.clear();
+  codec.Decode(packed, &relocations);
+
+  EXPECT_EQ(6, relocations.size());
+  // Initial relocation.
+  EXPECT_TRUE(CheckRelocation(0xc0de0000, 10000, relocations[0]));
+  // Two relocations, 4 byte offset deltas, 12 byte addend deltas.
+  EXPECT_TRUE(CheckRelocation(0xc0de0004, 10012, relocations[1]));
+  EXPECT_TRUE(CheckRelocation(0xc0de0008, 10024, relocations[2]));
+  // Three relocations, 8 byte offset deltas, -24 byte addend deltas.
+  EXPECT_TRUE(CheckRelocation(0xc0de0010, 10000, relocations[3]));
+  EXPECT_TRUE(CheckRelocation(0xc0de0018, 9976, relocations[4]));
+  EXPECT_TRUE(CheckRelocation(0xc0de0020, 9952, relocations[5]));
+}
+
+}  // namespace relocation_packer